Sonobuoys are expendable underwater listening devices typically employed for the detection, classification and location of underwater objects. Although models and capabilities vary, sonobuoys generally include a float, radio transmitter, a battery and a hydrophone attached to a wire for detecting sound under water. In its simplest form, the sonobuoy is a compact, self-contained package of electronics designed to be enter the water, separate into an underwater acoustic sensor and an on-the-surface radio transmitter, and relay the underwater acoustic signals it detects to some external system, where the radio frequency (RF) transmission is received and processed to detect and locate a detected object.
Sonobuoys generally lack the means for effective self-positioning, and current- and wind-induced drift of sonobuoys can have a detrimental impact on the effectiveness of sonobuoy systems arrayed as a distributed sensor field. Not only can the sonobuoys drift away from the area-of-interest, but buoy movement relative to other buoys in the field can reduce field integrity by creating coverage gaps in the field or clustering too many buoys in one area. Despite the significant advances made in the underwater detections, the most significant gaps still exist in the areas of responsive mobility and timely communication of acquired contacts; in short, it takes too long to communicate the positively detected signatures to external systems. Low bandwidth and operational range of communication links, and low mobility of the undersurface autonomous platforms within the existing onboard energy budgets are the key constraining factors of the current state of the art of sonobuoy technology.
Provided here is a multirotor mobile buoy providing for the detection, classification and location of underwater objects using self-contained electronics, and able to reposition by aerial means using a plurality of rotors. The multirotor mobile buoy additionally incorporates solar panels for recharging of on-board batteries enabling the flight and other functions, and comprises a buoyant assembly and extended tether in order to promote stability in dynamic, open ocean environments. The multirotor mobile buoy may be employed singly or as a swarm of underwater detection platforms, and may utilize its positioning ability to optimize the effectiveness of sonobuoy systems arrayed as a distributed sensor field.
These and other objects, aspects, and advantages of the present disclosure will become better understood with reference to the accompanying description and claims.